Facebook, Twitter, Linkedin are the big three but there are countless others ranging from closed B2B networks to niche, open networks. There are so many that it’s hard to know which ones you should be participating in and how much effort you should put into them. The answer is simple; you participate in every network that makes sense for you.
This doesn’t mean go nuts and start shot gunning all of them with the same posts. Pick one, start small, learn how to participate in it. Once you’ve mastered it, measure it. Is participating in this network moving you towards one of your goals? If so, keep participating; if not, drop it. Repeat this procedure for each Social Network you come across.
At some point you will hit a point where you can’t participate in all the ones that are performing well for you. Luckily, you have been measuring their effectiveness so you can easily determine which ones are most effective for you and which ones you need to abandon.
That is exactly how many Social Networks you should be participating in.